Immunity and the pathophysiology of chronic fatigue syndrome

Abstract:

The pathophysiology of chronic fatigue syndrome (CFS) remains unknown. The syndrome often follows a recognized or presumed infection and the disorder may therefore result from a disordered immune response to a precipitating infection or antigenic challenge.

Abnormalities of both humoral and cellular immunity have been demonstrated in a substantial proportion of patients with CFS. The most consistent findings are of impaired lymphocyte responses to mitogen and reduced natural killer cell cytotoxicity. Cutaneous anergy and immunoglobulin G subclass deficiencies have also been found.

Further studies are needed examining cytokine levels in serum and cerebrospinal fluid, and cytokine production in vitro in patients with CFS. Interpretation of the findings of published studies of immunity is limited by probable heterogeneity in the patient groups studied, and by the lack of standardization and reproducibility in the assays used.

The pattern of abnormalities reported in immunological testing in patients with CFS is consistent with the changes seen during the resolving phases of acute viral infection. These data provide circumstantial support for the hypothesis that CFS results from a disordered immune response to an infection. Longitudinal studies of immunity in patients developing CFS after defined infectious illnesses will provide the best means of further examining this hypothesis.

 

Source: Lloyd AR, Wakefield D, Hickie I. Immunity and the pathophysiology of chronic fatigue syndrome. Ciba Found Symp. 1993;173:176-87; discussion 187-92. http://www.ncbi.nlm.nih.gov/pubmed/8491097

 

Molecular approaches to epidemiologic evaluation of viruses as risk factors for patients who have chronic fatigue syndrome

Abstract:

One approach to understanding the chronic fatigue syndrome might be to carry out prospective studies of fatigue that occurs following infection with viral diseases of known etiology, such as influenza, hepatitis, and infectious mononucleosis. Among the viral parameters that should be evaluated are virus burden, variation of virus strain, sites of viral replication, and the state of the viral life cycle (e.g., latent or replicative). Immunologic studies should focus on the humoral and cellular responses to defined viral gene products to identify subtle, individual variations in immune recognition of specific viral subcomponents.

 

Source: Miller G. Molecular approaches to epidemiologic evaluation of viruses as risk factors for patients who have chronic fatigue syndrome. Rev Infect Dis. 1991 Jan-Feb;13 Suppl 1:S119-22. http://www.ncbi.nlm.nih.gov/pubmed/1850537

 

Immunological abnormalities in the chronic fatigue syndrome

Abstract:

The chronic fatigue syndrome is a disorder of unknown aetiology which is characterized by debilitating fatigue. Recent evidence has suggested that viruses may persist in the tissues of patients with chronic fatigue syndrome. A concurrent immunological disturbance is likely to be associated with the persistence of viral antigens.

Therefore, the humoral and cellular immunity of 100 patients who were suffering from chronic fatigue syndrome and that of 100 healthy, age- and sex-matched control subjects were compared. This study documents the frequent occurrence of abnormalities within the cellular and humoral immune systems of patients with well-defined chronic fatigue syndrome. Disordered immunity may be central to the pathogenesis of chronic fatigue syndrome.

In patients with chronic fatigue syndrome, a significant (P less than 0.01) reduction was found in the absolute number of peripheral blood lymphocytes in the total T-cell (CD2), the helper/inducer T-cell (CD4) and the suppressor/cytotoxic T-cell (CD8) subsets. A significant (P less than 0.001) reduction also was found in T-cell function, which was measured: in vivo by delayed-type hypersensitivity skin-testing (reduced responses were recorded in 50 [88%] of 57 patients); and in vitro by phytohaemagglutinin stimulation. Reduced immunoglobulin (Ig) levels were common (56% of patients), with the levels of serum IgG3- and IgG1-subclasses particularly (P less than 0.05) affected.

 

Source: Lloyd AR, Wakefield D, Boughton CR, Dwyer JM. Immunological abnormalities in the chronic fatigue syndrome. Med J Aust. 1989 Aug 7;151(3):122-4. http://www.ncbi.nlm.nih.gov/pubmed/2787888